It has become increasingly important to monitor temperatures on an integrated circuit (“IC”) die, or chip. For example, it is important to manage the on-die temperature in a multi-core SOC (“system on chip”) due to issues pertaining to the positive feedback mechanism associated with leakage current and temperature, in that leakage current results in increases in temperature within the die circuitry. A temperature sensor can be used to monitor the temperature of an electronic component, such as a CPU (“central processing unit”), GPU (“graphics processing unit”), MPU (“microprocessor unit”), SOC (“system on chip”), etc. When the temperature exceeds predetermined thresholds, the sensor may alert circuitry to slow down or even shut down the electronic component to reduce power consumption and thus reduce the temperature so that overheating that can cause destructive failure to the component may be prevented.
Typically, temperature sensors include a reference circuitry and a temperature measuring circuitry, wherein the temperature dependency is either proportional to absolute temperature (“PTAT”), that is, the measuring circuit outputs a voltage that increases in proportion to a temperature rise (i.e., has a positive temperature coefficient), or complementary to absolute temperature (“CTAT”), that is, the measuring circuit outputs a voltage that drops in proportion to a temperature rise (i.e., has a negative temperature coefficient). Further, DAC (“digital to analog converter”) based temperature sensors have been implemented relying on comparing a PTAT voltage and a CTAT base-emitter voltage. This approach, however, has suffered from DAC code-to-temperature non-linearity issues, i.e., it cannot achieve good linearity over a wide temperature range, resulting in poor temperature measurement accuracy.